JPS6459010A - Position detecting device - Google Patents

Abstract

PURPOSE:To perform position detection which has superior linearity and is accurate over a wide range by providing a detection signal electrode which has its electrode surface formed opposite the electrode surfaces of two reference signal electrodes arranged in the displacing direction of a detection body, and varying the electrostatic capacity between the electrodes. CONSTITUTION:The two reference signal electrodes 12 and 13 are applied with two kinds of reference signals phi1 and phi2 set in specific phase relation from an ALC circuit 17. Then when the detection body is positioned in the center and the two reference signal electrodes 12 and 13 and detection signal electrode 14 are equal in confrontation area, the two kinds of reference signals cancel each other at two timing points where they become opposite in phase, so the detection signal electrode 14 has no voltage variation. If the detection body is displaced to generate any difference in the confrontation area between the two reference signal electrodes 12 and 13 and detection signal electrode 14, on the other hand, the detection signal electrode 14 has voltage variation corresponding to the displacement position at two timing points where the two kinds of reference signals phi1 and phi2 become out of phase, so this is used as position information on the detection body.